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<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
</head>
<body>
	<script>
		/*[[Value]]*/
		var person = {
			name: "Jack"
		}
		/* 这里的创建了一个name的属性，属性值被设置成Jack，对属性值的任何修改，都将反映到该位置上 */


		/*[[Writable]]*/

/*		var person = {};
		Object.defineProperty(person, 'name', {
			writable: false,
			value: 'Jack'
		});

		alert(person.name); // Jack
		// person.name = 'P';

		delete person.name;

		alert(person.name); // Jack
*/


		/*[[Configurable]]*/

/*		var person = {};

		Object.defineProperty(person, 'name', {
			value: 'Jack',
			configurable: false
		});

		alert(person.name) // Jack

		person.name = 'b';
		delete person.name;

		alert(person.name) // Jack

		Object.defineProperty(person, 'name', {
			configurable: true
		})*/

		var person = {
			name: "Jack"
		}

		Object.defineProperty(person, 'name', {
			value: 'v'
		})

		person.name = 'b';

		alert(person.name)

	</script>
</body>
</html>